Sailfish OS being founded on using gestures in order to do something here is a suggestion, swipe selection. This much used tweak in jailbroken iOS devices is just something every touchscreen UI should have.
Simply swiping along the keyboard moves the cursor making it very easy to move to the section you want to edit. Additionally when swiping is started from the shift key it highlights the text, so selecting a part of the text is very easy too. Overall there is no need to tap anything outside keyboard.
Demonstrated on this Youtube video

I really like the native cursor movement implementation but it does only make real sense on a phone, where you are able to get your thumb to reach the desired screen position. So this 'swipe selection' is a really good idea to implement it so you can use it on the Jolla Tablet. :)